This invention relates in general to optical apparatus. More specifically, it relates to an optical structure which is neutral to normal light, but which blocks, or substantially reduces, the transmission of highly collimated light.
There is a long recognized need for a material, device, or system which will pass ordinary light with little or no adverse affect on the quality of the viewed image, but which will block, or at least reduce substantially, the transmission of highly collimated light, as from a laser. The invention is needed because the human eye and other optical devices such as cameras focus laser light to a small point thereby increasing the intensity of the light. Focusing optics are therefore their own worst enemy when subjected to laser light. Heretofore the principal solution to this problem has been to screen out radiation at the anticipated wavelength of the laser light, but to pass other wavelengths. To date, there are no laser shields known to applicant which are neutral to ordinary light and which reliably block laser light of any wavelength. In particular, there are no known laser shields which have these characteristics which are also readily formed into lenses for eyewear, windshields, windows and the like.
It is therefore a principal object of the present invention to provide a laser shield which is optically neutral to ordinary light, but which attenuates or blocks laser light.
A further object is to provide a laser shield with the foregoing advantages which operates independently of the wavelength of the laser light.
Another object of the present invention is to provide a laser shield that can be formed into a sheet of material that is substantially transparent to ordinary light and which can be formed into a wide variety of optical elements, such as eyewear, windshields and view ports.
A further object is to provide a laser shield in the form of a sheet material which can have a flat or curved geometry.
Another principal object of the invention is to form an extended, sheet-like laser shield having a resolution superior to the resolution of the component optical cells forming the sheet.
A further object is to provide a laser shield with the foregoing advantages which can be manufactured using conventional techniques and standard materials.
Still another object is to provide a laser shield which is comparatively thin, lightweight, and durable under normal use conditions.
Yet another object is to provide a laser shield with the foregoing advantages which ca be constructed to have acceptably low chromatic and spherical aberrations.